1. Field of the Invention
The present invention relates to the destruction of acetone peroxides, and, more especially, to the destruction of by-product acetone peroxides present in various reaction mixtures.
2. Description of the Prior Art
In certain known processes, particularly for the preparation of phenols and diphenols, acetone is contacted with an oxidizing agent such as hydrogen peroxide and the acetone peroxides are formed as by-products.
Thus, in the industrial synthesis of phenol from cumene, acetone and its by-products such as 2-phenyl-2-propanol are formed to a certain extent from the final product phenol. It has long been sought to enhance the phenol productivity of the process, in particular by oxidizing the 2-phenyl-2-propanol to cumenyl hydroperoxide, which itself splits into phenol + acetone. This oxidation may be carried out by the addition of hydrogen peroxide to the reaction mixture, as described in FR 1,077,475, to form acetone peroxides.
In the same manner, in the process for the preparation of hydroquinone from diisopropylbenzene described in EP-A-21,848, the productivity is again improved by the addition of hydrogen peroxide in order to oxidize certain by-products to diisopropylbenzene bis(hydroperoxide). This results in, as above, the formation of acetone peroxides in the reaction medium.
Another such process in which acetone peroxides are formed entails the hydroxylation of phenol, of substituted phenols or of phenol ethers, by hydrogen peroxide, in an acetone medium and in the presence of synthetic zeolites, described in the French Patent published under number 2,523,575. This process permits the preparation of diphenols, substituted diphenols or substituted phenols. However, during distillation of the acetone formed during the reaction or employed as solvent, and the distillation of the final product phenol or diphenols, the acetone peroxides produced by reaction between the oxidizing agent, such as hydrogen peroxide, and the acetone are either partly concentrated in the distillation residue, or partly entrained, and can crystallize in different elements of the apparatus.
Therefore, a potentially serious risk of explosion exists.